The invention concerns an adhesive for floor coverings based on an aqueous dispersion for laying floor coverings with a backing of textile materials or foamed plastics.
Heretofore the adhesives used primarily for such coverings consisted of balsam resin in combination with polyvinyl ether in a methanolic solution. They contain usually large amounts of fillers, particularly calcium carbonate powder. This type of adhesive is generally called "light plastic cement". Its characteristic properties are:
(a) long open assembly time, PA1 (b) good wet stickiness, that is, there is no accidental detachment of the covering from the floor, even immediately after the laying, PA1 (c) good adhesive strength, PA1 (d) good waterproofness, PA1 (e) possibility of making corrections to a certain extent during the laying, a measure of which can be seen in the fact that the adhesive is ropy during the hardening. PA1 (f) fire hazards based on the content of the methanolic solution and PA1 (g) physiological hazards based on its methanol content, which requires special precautions at the work place of the processor and adequate ventilation when being applied. PA1 (a) 100 parts by weight of an aqueous polymer dispersion having a solids content of from 30% to 70% by weight of the total weight of said dispersion, the solids content consisting of synthetic resin particles of at least a bimodal particle size distribution wherein the majority of the larger particles is at least twice the size of the majority of the smaller particles and where the majority of the larger particles has a particle size distribution of from 0.5 to 3 .mu.m and the majority of the smaller particles has a particle size distribution of from 0.1 to 1 .mu.m, PA1 (b) from 30 to 120 parts by weight of a plasticizing mixture of (1) from 45% to 100% by weight of a synthetic resin plasticizer/soft resin mixture with 1 part by weight of said plasticizer per from 1 to 20 parts by weight of said soft resin, (2) from 0 to 20% by weight of at least one organic solvent, and (3) from 0 to 35% by weight of at least one hard resin and PA1 (c) from 0 to 60% by weight of said adhesive of inert finely-divided fillers. PA1 (a) 100 parts by weight of an aqueous polymer dispersion with a solids content of from 30% to 70% by weight of the total weight of the dispersion, where the solids content consists of synthetic resin particles of various sizes, where the majority of the larger particles is double the size of the majority of the smaller particles, and where the majority of the larger particles has a particle size of from 0.5 to 3 .mu.m and the majority of the smaller particles has a particle size of 0.1 to 1 .mu.m, PA1 (b) 30 to 120 parts by weight of a plasticizer/soft resin mixture with 1 part by weight of synthetic resin plasticizer per 1 to 20 parts by weight of soft resin. PA1 (a) 100 parts by weight of an aqueous polymer dispersion having a solids content of from 30% to 70% by weight of the total weight of said dispersion, the solids content consisting of synthetic resin particles of at least a bimodal particle size distribution wherein the majority of the larger particles is at least twice the size of the majority of the smaller particles and where the majority of the larger particles has a particle size distribution of from 0.5 to 3 .mu.m and the majority of the smaller particles has a particle size distribution of from 0.1 to 1 .mu.m, PA1 (b) from 30 to 120 parts by weight of a plasticizing mixture of (1) from 45% to 100% by weight of a synthetic resin plasticizer/soft resin mixture with 1 part by weight of said plasticizer per from 1 to 20 parts by weight of said soft resin, (2) from 0 to 20% by weight of at least one organic solvent, and 3) from 0 to 35% by weight of at least one hard resin and PA1 (c) from 0 to 60% by weight of said adhesive of inert finely-divided fillers.
These adhesives, however, suffer the drawbacks of